The present invention relates to floatation garments such as lifejackets and immersion suits. More specifically the present invention relates to floatation garments provided with thermal insulation to safeguard the wearer from the potentially fatal consequences of immersion in cold water.
Lifejackets are provided for use in emergency situations, such as the sinking of a ship or the downing of an aircraft in water. As will be well understood a lifejacket gives the wearer additional buoyancy and helps to safeguard against drowning. Since, in an emergency situation, it is not possible to select ones lifejacket (one simply dons the lifejacket closest to hand), lifejackets follow the simple principle that one size fits all, at least for adults. At the upper and lower extremes this may cause problems, but generally all lifejackets are designed to fit 90% of the adult population. Variations in size are compensated for by securing ties on the lifejacket.
Following the tragic loss in the Baltic Sea of the roll on/roll off ferry Estonia, when there was considerable loss of life, a complete review of life saving procedures, standards and equipment took place. The circumstances surrounding the deaths of the unfortunate passengers drew attention to the need for a lifejacket which would not only support a person in water, but which would also materially assist in retaining important body warmth.
It is not generally appreciated that immersion in sea water, even in temperate climates, causes heat loss. Over a period of time, determined by the temperature of the sea and the persons size and weight, this leads to hypothermia and death follows quickly, either as a result of drowning because one is no longer able to support ones head out of the water or through heart failure. Research has shown that if a lifejacket is designed so that some of the required buoyancy also provides thermal protection of the torso and head, then the time the wearer will remain conscious in cold water is considerably extended from perhaps fifteen minutes to more than three hours. Thermal protection of the torso should include head, neck, armpits and groin, where the bloodstream is close to the skin and thermal protection is most important. The human body preserves body heat in a cold environment by reducing blood circulation in arms and legs. Thermal protection of these extremities is therefore less important.
Currently, the SOLAS lifejacket, which is the industry standard, provides buoyancy and materially helps to prevent a person from drowning. It will also support an unconscious person in a position where the mouth and nose are clear of the water. However, the SOLAS lifejacket offers virtually no thermal protection, and its clumsiness materially restricts the wearer""s mobility.
An immersion suit is defined in the norm ISO/DIS 15027 1, 2, 3 as a suit intended to protect the wearer from the effects of immersion in cold water. There are two varieties of immersion suits, being constant wear suits (an immersion suit, designed to be routinely worn in anticipation of accidental immersion in cold water, but permitting physical activity by the wearer to such extent that actions may be undertaken without undue encumbrance. The suit can also be worn for foul weather protection) and abandonment suits (an immersion suit designed to permit rapid donning in the event of an imminent unintended immersion in cold water).
The difficulty resides in the making of such an immersion suit which shall meet the standards of thermal insulation (today""s standard specifies that the body core temperature may not drop more than 1 degree Celsius per hour) as well as prevailing standards for buoyancy (when requested), and yet will fit most of the (adult) sizes without significant restriction of movement, and which also can be easily and correctly donned by an untrained wearer within one minute.
It is an object of the present invention to provide a thermally insulating floatation garment, such as a lifejacket or an immersion suit (including constant wear suits and abandonment suits), which offer a predetermined thermal insulation in water even when worn by persons of different sizes.
It is another object of the present invention to provide a lifejacket for use in emergency situations which provides the wearer buoyancy and thermal insulation.
It is yet another object of the present invention to provide a lifejacket for use in emergency situations which is capable of fitting a wide range of adult sizes.
It is yet a further object of the present invention to provide an immersion suit, in particular an abandonment suit, which allows the wearer increased freedom of movement as compared with conventional abandonment suits.
It is yet another object of the present invention to provide a constant wear suit which provides freedom of movement to the wearer whilst keeping to a minimum the flow of water into and out of the suit.
According to the present invention there is provided a floatation garment comprising an elastic layer shaped to fit at least around the torso of a wearer and to stretch to an extent between a minimum and a maximum depending on the size of the wearer, and a plurality of thermally insulating panels which are attached with respect to the elastic liner and/or with respect to one another such that they slidably overlap one another.
It will be understood that the thermally insulating panels are used in the floatation garment of the present invention to provide thermal insulation. They can be made of a material which provides thermal insulation but no or substantially no buoyancy such as for example the material of wet suits. Preferably, the thermally insulating panels are however made of a material which provides not only thermal insulation but which also gives buoyancy. In this way, the volume of other buoyant elements of the garment, such as an inflatable bladder which is preferable provided in the garment to provide buoyancy and to self-right a wearer even when he is unconscious, may be reduced. The thermally insulating panels may in particular be made of a foam material which is preferably enclosed in a cover. By reason of the panels being slidable relative to each other as the garment is stretched, it can fit a wide range of sizes without requiring any alterations or adjustments to be made to it. When the garment is worn by a small person it is not stretched to any significant extent and the thermally insulating panels overlap with each other to their fullest extent. As the size of the wearer increases the garment will stretch causing the foam panels to slide apart, but the wearer""s torso remains enclosed by the foam panels.
The thermally insulating panels may be attached to one or both sides of the elastic layer. It is preferable to arrange the thermally insulating panels on an inner side of the elastic layer, i.e. on the side facing the wearer. In this way, these panels are pressed by the elastic layer against the wearer""s body so that flow of water between the wearer""s body and the thermally insulating panels is avoided and an effective thermal insulation can be achieved.
The elastic layer may comprise an elastic rubber layer, in particular a Neoprene layer, which is preferably lined on at least one side with a knitted stretch layer. The thermally insulating panels may comprise a foam panel, in particular a closed cell foam panel, which is preferably enclosed in a cover. The foam panels may for example be comprised of PU (polyurethane), PO (polyolefine), PVC (polyvinyl chloride), nitril rubber foam or of a mixture of these materials.
Preferably, the thermally insulating panels are arranged between an elastic inner lining material, which is worn against the skin, and the elastic layer. This inner lining protects the wearer""s skin from chafing by the panels. It can also be used to fix one or more of the thermally insulating panels, in particular by stitching, to keep it on its place in the garment. Preferably, the inner lining is stitched or otherwise joined to the elastic layer along its edges to enclose the thermally insulating panels. The inner lining may be comprised of stretch elastane such as Lycra.
It is preferable that the thermally insulating panels overlap one another to form a continuous layer of thermally insulating material even when the elastic layer is stretched to the maximum extent or in other words to limit the stretch in the elastic layer or in other words in the garment so that the thermally insulating panels do not slide so far apart that they actually cease to overlap each other. This would leave thermally open areas in the garment through which heat would escape.
The floatation garment of the present invention can be designed to comfortably fit for example children having a height of 1.40 m or less and adults of varying build up to and including 101 kgs in weight and over and 1.96 m in height and over. Tests have shown that the garment can compensate at least for the indicated variation in size. Where required a junior version or a larger version of the floatation garment can also be provided.
The floatation garment may take the form of a lifejacket or of an immersion suit (including constant wear suits and abandonment suits). When used in both a constant wear suit or an abandonment suit the present invention has the advantage over the prior art of allowing considerable freedom of movement, whilst preventing, or at least minimising the free flow of water around the wearer""s torso. This is because the thermally insulating panels slide freely over one another as the wearer moves around, but are still held close to the wearer""s torso by the elastic layer.
When used as a lifejacket the floatation garment may take the form of a jerkin or sleeveless coat. Conveniently it also includes a crotch piece which allows it to be secured around the lower body and upper legs to protect the groin area. Preferably, the garment also comprises a spray hood and at least one inflatable bladder or chamber designed not only to provide additional buoyancy but also preferably to self-right an unconscious person.
When used as an immersion suit (including constant wear suits and abandonment suits) it may also comprise arms and legs. In a constant wear suit or an abandonment suit the garment may also be provided with an outer layer of hard wearing, waterproof material, such as Cordura, polyester, aramids or nylon.
Preferably, arm, neck and leg holes in the garment are elasticated to form a tight seal when worn and thereby prevent or, at least minimise, the flow of water under and through the garment. To secure the garment when worn, belts, straps and webbing may be provided. To prevent or minimise flow of water between the garment and the wearer""s body, one free edge portion of the elastic layer preferably overlaps the opposite free edge portion of the elastic layer over a distance depending on the size of the wearer and the garment comprises a closure enabling to secure both free edge portions to one another for different distances of overlapping, the closure comprising in particular touch and go fasteners such as Velcro strips.
An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: